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Abstract The crystal structures, magnetic properties and electronic structures of pseudo-binary compounds Pr 5 Si x Ge 3-x were investigated. With the increase of the Ge content, structure of Pr 5 Si x Ge 3-x gradually changes from the tetragonal Cr 5 B 3 -type to the hexagonal Mn 5 Si 3 -type. For the compounds with the tetragonal structure, the unit cell volumes as well as the magneto-crystalline anisotropy energy (MAE) increase with the Ge content, leading to the diminishing of the magnetization and the maximum magnetic entropy changes -Δ S M. As compared to the binary compound Pr 5 Si 3 , the intermetallic compounds with Ge doping show broader working temperature span and considerably large relative cooling power (213.9, and 184.8 J kg−1 at ΔH = 50 kOe for Pr 5 Si 2.5 Ge 0.5 and Pr 5 Si 2 Ge, respectively). For the hexagonal compound Pr 5 Ge 3 , a large MAE and an easy magnetization direction close to c axis (polar angle θ ∼7°) were calculated, which is related to the macroscopic magnetic transition behavior at low temperature. Highlights • Ge doping changes the structures of Pr 5 Si x Ge 3-x from tetragonal to hexagonal type. • Ge doping increases the MAE and leads to the diminishing of the magnetization. • The RCP values of Pr 5 Si x Ge 3-x (x = 2.5, 2.0) are larger than that of Pr 5 Si 3. • The large MAEs affect the magnetic behaviors of Pr 5 Si x Ge 3-x at low temperature. [ABSTRACT FROM AUTHOR]

Abstract: The structure and magnetic properties of Pr5Si3 compound have been investigated. A large reversible magnetic entropy change was observed at about 47K accompanied with a second-order magnetic transition from the ferromagnetic to paramagnetic state. The maximum values of −ΔS M are 11.6 and 6.0Jkg−1 K−1 at 47K, corresponding to the applied magnetic field changes of 50 and 20kOe, respectively. The study on the magnetocaloric effect of the light rare-earth based compound, may open a field in searching for new magnetic refrigerant materials. [Copyright &y& Elsevier]

Deep-red-emitting Mn4+ activated oxide phosphors are the hot research topic due to their potential applications in indoor plant cultivation LEDs. In this paper, a novel double-perovskite LiLaMgTeO 6 :Mn4+ phosphor was firstly prepared by high-temperature solid-state reaction method and its structure of the phosphor was determined by X-ray diffraction (XRD) and Rietveld refinement. Density functional theory (DFT) calculations using VASP provide an insight into the bandgap and electronic structures of the LiLaMgTeO 6 host. Under UV or blue excitation, LiLaMgTeO 6: Mn4+ shows a good stability and bright far-red light in the 540–800 nm range with the maximum at 708 nm, which matches well with the absorption band of phytochrome P FR , indicating its potential application in improving plant growth. The optimal Mn4+ doping concentration was approximately 0.6 mol%. Furthermore, a white-LEDs device made of a 365 nm chip coated with present phosphor and commercial green, blue phosphors was designed for indoor plant cultivation. The results indicate that the LiLaMgTeO 6 : Mn4+ phosphor possesses great application prospect in white-LEDs for plant cultivation. Image 1 • Deep-red-emitting Mn4+ activated double perovskite LiLaMgTeO 6 phosphors were firstly synthesized. • The bandgap and electronic structures of the LiLaMgTeO 6 host were performed. • LiLaMgTeO 6 : Mn4+ phosphors exhibited far red light centered on 708 nm excited by ultraviolet light and blue-light. • The crystal field strength and nephelauxetic effect influencing the Mn4+ emission energy were also analyzed. • A white-LEDs device for indoor plant cultivation was manufactured. [ABSTRACT FROM AUTHOR]

Abstract: The phase structures and the phase transition temperatures among α, β and γ phases of CuI have been studied by using X-ray diffractometer with high-temperature camera. The phase transition temperatures are found to be obviously lower than the previous results. And the X-ray diffraction results have allowed the refined structure for β-CuI to be determined in space group R-3m, with Cu+ in 6(c) sites and I− in 3(a) and 3(b) sites, which is different from other reports and has been approved to be a transient phase in other articles. The results are also discussed and attributed to the pressure effect. [Copyright &y& Elsevier]